Crosstalk between leukemic blasts and the BM microenvironment contribute to leukemic transformation

白血病原始细胞和骨髓微环境之间的串扰有助于白血病转化

• 批准号: 10584524
• 负责人: Adrienne M. Dorrance
• 金额: $ 35.73万
• 依托单位: OHIO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-03-04 至 2023-03-02
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10584524
• 关键词: Acute Myelocytic Leukemia; Antibodies; Binding; Biology; Blast Cell; Blocking Antibodies; Blood; Bone Diseases; Bone Marrow; Cell Line; Cell physiology; Cells; Chromosome abnormality; Clinical; Combined Modality Therapy; Cytogenetics; DNA Sequence Alteration; Data; Disease; Epithelium; Exhibits; FLT3 gene; FLT3 inhibitor; Feedback; Frequencies; Genetic; Goals; Growth; Growth Factor; Hematological Disease; Hematopoietic Neoplasms; Hematopoietic stem cells; In Vitro; Knockout Mice; Leukemic Cell; Malignant - descriptor; Malignant Neoplasms; Marrow; Messenger RNA; Modeling; Molecular; Monoclonal Antibodies; Mus; Mutate; Mutation; Myelogenous; Patients; Phenotype; Physiological; Play; Preleukemia; Process; Prognosis; Protein Secretion; Proteins; Publishing; Recombinants; Relapse; Reporting; Resistance; Role; Sampling; Series; Signal Pathway; Signal Transduction Pathway; Testing; Therapeutic; Work; acute myeloid leukemia cell; angiogenesis; antileukemic activity; autocrine; cell growth; clinical development; cohort; conditional knockout; effective therapy; efficacy evaluation; endothelial stem cell; experimental study; in vivo; leukemia; leukemia initiating cell; leukemia treatment; leukemic stem cell; leukemic transformation; leukemogenesis; mRNA Expression; mesenchymal stromal cell; mouse model; novel; novel therapeutics; paracrine; patient derived xenograft model; pre-clinical; preclinical study; response; stem cell function; therapeutic target; therapy resistant

PROJECT SUMMARY Acute myeloid leukemia (AML) is a clonal, highly heterogeneous malignancy of the blood and bone marrow with poor prognosis. Along with genetic mutations within the leukemic cells themselves, alterations in the BM microenvironment (BMM) also play an important role in leukemia transformation, therapy resistance, and relapse. Thus, to develop effective AML therapies, it is critical to understand how intrinsic genetic alterations in the leukemic blasts cooperate with the BMM to facilitate leukemogenesis. We identified that the secreted protein Epithelial Growth Factor Like 7 (EGFL7) is highly expressed in a large cohort of AML patients and is associated with poor prognosis. We further demonstrate that: 1) EGFL7 protein increases blast cell growth and impacts on leukemic stem cell (LSC) function; 2) leukemic bone marrow mesenchymal stromal cells (MSCs) express and secrete EGFL7 at increased levels compared to normal MSCs ; 3) normal MSCs exhibit increased growth and survival in response to a recombinant EGFL7 protein and 4) Egfl7 is increased in AML blasts, but not in pre- leukemic hematopoietic stem and progenitor cells (HSPCs) from a primary Mll PTD; Flt3 ITD murine AML model. Based on our work, we hypothesize that aberrant EGFL7 expression by leukemic cells and BM niche cells contribute to leukemogenesis and is a relevant target for treatment for AML patients. The goal of our proposal is to fully characterize the phenotypic contributions of EGFL7 to myeloid leukemogenesis, dissect its molecular mechanism(s), and determine the therapeutic benefit of targeting EGFL7 in AML. We are planning to achieve these goals through the following specific aims (SA): SA#1: To demonstrate the importance of EGFL7 in leukemic cells to alter the BM microenvironment to promote leukemogenesis. Here, we hypothesize that EGFL7 promotes a positive feedback loop between leukemic cells and the BM microenvironment contributing to disease initiation and progression. We will test this hypothesis with a series of in vitro and in vivo experiments organized in three tasks. In Task 1 we will examine the contribution of EGFL7 in the BMM towards the initiation of AML using our Mll PTD; Flt3 ITD and Egfl7fl/fl conditional knock-out mouse models. For Task 2 we will determine how alterations in the expression of EGFL7 effects MSCs in leukemogenesis. Task 3 we will characterize the molecular mechanisms of Egfl7-dependent signaling pathways in MSCs; SA#2: To investigate anti-leukemic activity of a monoclonal EGFL7 blocking antibody (Parsatuzumab) in combination with a FLT3 inhibitor (Gilteritinib), using patient derived xenograft (PDX) murine models and primary genetic murine models of AML. Here, we propose to conduct in vitro and in vivo preclinical studies using AML cell lines, primary AML samples and two murine models of FLT3 mutated AML to evaluate the efficacy of targeting the autocrine and paracrine action of EGFL7 in AML. Overall, this proposal seeks to define the role of EGFL7 in the cross-talk between the BMM and leukemic cells and to generate preclinical data to support clinical development of anti-EGFL7 monoclonal antibodies in combination with FLT3 inhibitors for FLT3 mutated AML.

项目摘要 急性髓样白血病（AML）是血液和骨髓的高度异质性恶性肿瘤 预后不良。与白血病细胞内的基因突变一起，BM的改变 微环境（BMM）在白血病转化，耐药性和 复发。因此，要开发有效的AML疗法，重要的是要了解内在的遗传改变如何 白血病与BMM合作以促进白血病。我们确定了分泌的蛋白质 上皮生长因子（例如7（EGFL7））在大量AML患者中高度表达，并且相关 预后不良。我们进一步证明：1）EGFL7蛋白增加了爆炸细胞的生长并影响 白血病干细胞（LSC）功能； 2）白血病骨髓间充质基质细胞（MSC）表达和 与正常的MSC相比，分泌EGFL7的水平增加； 3）正常的MSC表现出增长增加和 响应重组EGFL7蛋白和4）EGFL7的生存率在AML爆炸中增加，但在前 来自原发性MLL PTD的白血病造血干和祖细胞（HSPC）； FLT3 ITD鼠AML模型。 根据我们的工作，我们假设白血病细胞和BM细胞的异常EGFL7表达 有助于白血病，是AML患者治疗的相关靶标。我们提议的目标是 为了完全表征EGFL7对髓样白血病发生的表型贡献，请剖析其分子 机理，并确定靶向AML中EGFL7的治疗益处。我们正在计划实现 通过以下特定目标（SA）：SA＃1：证明EGFL7在 白血病细胞改变BM微环境以促进白血病。在这里，我们假设EGFL7 促进白血病细胞和BM微环境之间的正反馈回路，导致疾病 启动和进展。我们将通过组织的一系列体外和体内实验来检验该假设 在三个任务中。在任务1中，我们将研究EGFL7在BMM中对AML启动的贡献 使用我们的MLL PTD； FLT3 ITD和EGFL7FL/FL条件敲除鼠标模型。对于任务2，我们将确定如何 EGFL7表达的改变在白血病中影响MSC。任务3我们将表征 MSC中EGFL7依赖性信号通路的分子机制； SA＃2：调查抗Leukemic 单克隆EGFL7阻断抗体（parsatuzumab）与FLT3抑制剂的活性 （Gilteritib），使用患者衍生的异种移植（PDX）鼠模型和AML的主要遗传鼠模型。 在这里，我们建议使用AML细胞系，主要AML样品进行体外和体内临床前研究 FLT3的两个鼠模型突变AML，以评估靶向自分泌和旁分泌的功效 EGFL7在AML中的作用。总体而言，该提议旨在确定EGFL7在 BMM和白血病细胞并生成临床前数据以支持抗EGFL7的临床发展 单克隆抗体与FLT3突变AML的FLT3抑制剂组合。